Biomechanical Comparison of Tension-Band Wiring Fixations in accordance with Kirschner Wires Placement Modes for Olecranon Fractures: A 3D-Finite Element Analysis

Mun-Sik Ko; Yun-Mi Kim; Jin-I Choe; Song-Gun Pak; Jung-Hyok Ho; Tong-Won Mun

Abstract

Background: Tension-band wiring is a widely accepted fixation technique and remains a standard method of surgical treatment in displaced olecranon fractures. There are 2 techniques according to the Kirschner wires (K-wires) placements; one is to insert the K-wires into the intramedullary canal of the proximal ulna and the other is provided by those anchored into the anterior cortex of the ulna. The purpose of this study was to compare biomechanical properties of the two fixation methods in olecranon fractures. Method: Biomechanical comparison was undertaken using 3D geometrical and FEM (Finite Element Method) models of olecranon fractures divided into 3 sites according to Colton’s classification (types I, II and III) and fixed with tension-band wiring by the 2 techniques which include K-wires placed parallel in the intramedullary canal of the proximal ulna and those placed obliquely into the anterior ulnar cortex distal to the coronoid process for bicortical purchase, supplemented with a monofilament tension-band loop. Results: Under bending and axial compression loads, the values of displacement of the latter in fractures of Colton types I and III were significantly lower than in the former. The latter mode showed that the stiffness in types I and II were lower compared with the former technique during the two loads. Conclusion: For Colton types I and III fractures, tension-band wiring by K-wires anchored into the anterior cortex of the ulna is more stable than technique using K-wires inserted into the intramedullary canal, but the latter increases the stability in the type II fracture compared with the former.

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